Improved method of preventing decay in the timbers of bridges



@initrd tats?, gettati @Wire AUGUSTUS ALLEN, OF CASS GOUN-TVY, MICHIGAN.

Letters Patent N 106,647, dated August 23, 1870.

IMPROVED METHOD OF PREVENTING-,DECAY IN' THE TIMBERS OF. BRIDGES, BUQILD- ING-S, acc.

The Schedule referred to in these Letters Patent: and making part 0f the same.

I, AUGUSTUSl ALLEN, of the county of Cass and State ot' Miihigan, have invented certain Improvements in the Mode oi' Preserving Thnberfrom Decay, of whit-h the-bllowing is a speeitieation.

The nature ofl nly invention relates to a method of' preservugtixnber, through the agency of a peculiarly constructed cover or covers, made ot zine or other analogous substances, the object being to pro-'idemeans whereby the foundation timbers of buildings, striugers of bridges, and wooden butments may be ineased, and

preserved to a great length 'of' time.

Iihe accompanying drawing shows a vertical longitudinal Kiew, through thedianleter of' a device, ein-' bodying my invention, in whioh y A represents one ot' the stringers of a railroad bridge.

B are tbebutments.

C are tbe'pedestals or supports. These supports are shaped like au hour-glass, and pass through the case, D, having air-tight iittings, as seen at E, for the purpose of allowing vibratory motion of the stringers A:

l is a. trausve1seseotion of the ties; and

G represents the rails of a railroad track.

.lhese-pedestals may be attached to the stringers and ties in any suitable manner. The lowerpedestals, G2, need not be used when the butinents B are made ot' wood and eased,ras the stringers may rest dir'eotly on the butlneuts, with these eases attached, as seen at H.

The case D must be made enough larger than the Stringer to allow ot' all probable vibration of ythe Stringer Within the case.

Foundations of' buildings may be made of wood, and iuoased with air-tight eases, made ot'zinc, in the uranner shown at B,at a. less cost than stone, and nearly as lasting, the trout i'aces of' wbiohinay be impressed with ornamental iigures, as desired.

`Door-sills, and other timbers much exposed to die weather, may be capped on the top and sides most exposed to decay, and not wholly inoased, thereby arresting decay for a long tin1e,but, \vben the superstructure is heavy, and rests on smalls'urt'aoes that would be likely to break or damage the case, the pedestals C should be used.

The great durability of zinc, when not exposed to wear, is well understoodl' Sueb timbers as are inclosed irrtight eases should be well seasoned before being ca s'ed.

Having t-hus fully described m y` invention,

rlhe air-tigbtcas'e D, having openings to receive the pedestals C, when vconstructed and arranged as and for the purposes setforth.

AUGUSTUS ALLEN.

Witnesses:

ELAM Heumen, CHAUNGEY L. LEE. 

